Applications of ionic liquids to electrolytes and plasticizers of electrolytes

Abstract

Ionic liquid are rapidly gaining interest as replacements for traditional organic solvents used in chemical process. They were initially developed by electrochemists for use as electrolytes in batteries or for metal electrodeposition. In spite of the important applications, physical and thermodynamic properties are hardly presented on the literature. Prior to the main experiments for application of Buthylmethylimidazolium ionic liquids to electrolytes, three ionic liquids, BMImBr, BMImI and $BMImBF_4$, were synthesized and physical properties were measured. N-alkyl-N-vinyl-2-pyrrolidinonium and N-alkyl-N-methyl-2-pyrrolidinonium appear high ionic conductivity due to π orbital in the vinyl functional group and wide electrochemical stability (3 or 4 V) and possess a good solvent character and thus might be used for potential electrolytes and green solvents. Lithium doped Buthylmethylimidazolium ionic liquids was proven to be highly conductive, electrically stable (3 ~4.7 V) by thermal analysis and qualitative analysis from Li-NMR and possess a good solvent character Therefore, all these ionic liquids including Buthylmethylimidazolium ionic liquids and N-alkyl-N-vinyl-2-pyrroli-dinonium and N-alkyl-N-methyl-2-pyrrolidinonium might be used for potential electrolytes and platicizers of electrolytes in Lithium ion batteries.